George Bernard Shaw once said that Britain and America are two countries separated by a common language. Nowhere is that gulf more apparent than in the difference between the car and the automobile.

There's a lot more to the difference between US and UK cars than simply filling them with gas or petrol. Even the unit of measurement, the gallon, is different. A US Gallon is only 0.833 imperial gallons even though they share the same name. Equally words like bonnet (hood), boot (trunk), saloon (sedan) and estate car (station wagon) are not any more interchangeable than driving on the wrong side of the road or steering a right-hand drive car.

American cars have always had a reputation for being bigger and brasher, while UK cars are known for being quieter and more fuel efficient, on the whole. And here lies the rub. Drivers in the UK are far less lightly taxed on fuel than their counterparts in the US. The current price for fuel in the US, according to petrolprices.com , is about $0.92 per litre (£0.60) compared to about £1.40 per litre in the UK. This is because drivers in the US pay just 6% in tax for their fuel, while UK drivers pay about 40% -- a massive difference.

Despite cheaper fuel, there are signs are that the US market is changing. More fuel efficient vehicles are becoming increasingly popular, with the Mini and Fiat 500 seen increasingly on US roads. Hybrid vehicles, such as the Prius are also a much more common sight.

But things are changing. Recently, there appears to be a growing trend towards buying smaller and more fuel efficient vehicles. The Mini is hugely popular as is the tiny Fiat 500, and Prius’s are an increasingly common feature on the American highway. Moreover, vehicles that might be considered large in the UK, say a 3-Series BMW or an E-Class Mercedes, are increasingly popular in the land of the Cadillac.

But although the UK and US markets might be becoming more similar, the cars themselves remain as different a London black cab and a New York Yellow cab. At the top end of the market things remain poles apart. Take limousines for example. British limousines like the Rolls Royce and Daimler tend to be a lot boxier but more stately than their US counterparts, such as the Lincoln or the Cadillac, which is generally lower and longer. The stretch limo is a form of car that is native to the US and has never been built in the UK.

Both the US and the UK have a long tradition of sports cars. Think of the UK and you think of Jaguar, Aston Martin and Lotus. Although the speeding limit is much lower in the US, it is generally considered to be a much quicker country to drive around in. Which is why, perhaps, the American sports car tends to be a throatier, more powerful affair, a throwback to the muscle cars of yore. Think of the difference between a classic Jaguar XJS and a classic American sports like Oldsmobile or a Pontiac Firebird or the iconic Ford Mustang. The former is a nimble car, quick off the gas, great at cornering. The latter are built for the open road, much faster for the straight lines of the American continent.

The Brits can do big too. The Land Rover and Range Rover's remain a class apart in the 4x4 market. But like their limo siblings, the UK Sports Utility Vehicle (SUV) is also boxy when compared to the more muscular Hummer.

Sadly the UK mid market has gone into decline in recent years. Rover, its last big car manufacturer engine has stopped ticking. But for the US car manufacture motors on.